Before Stephen Strange (Benedict Cumberbatch) becomes a mystic in Marvel’s Doctor Strange, he endures several years of training under the Ancient One (Tilda Swinton). When Swinton was first announced as Marvel’s white, female Ancient One, many fans and critics were confused. Scott Derrickson’s film was accused of whitewashing the original character, who first appeared in Marvel comics in the early 1960s as a Tibetan old man.

After letting the whitewashing controversy percolate for a few weeks, Marvel announced that Tilda Swinton’s version of the Ancient One was a Celtic mystic, and that the character’s ethnicity had been changed to appease the Chinese film market, which may not necessarily have accepted a Tibetan lead. Despite the MCU’s Ancient One being a Celtic rather than Tibetan mystic, nothing else in Doctor Strange’s world has been tampered with in order to reflect that change. Swinton’s character still operates out of the fictional Tibetan city of Kamar-Taj, which means the set pieces behind her are Asian-inspired.

In Doctor Strange, Stephen asks Mordo, “Just how ancient is she?” and Mordo replies that no one knows for sure. “The Ancient One” isn’t a single person, so much as a title that’s passed down from leader to leader. The Ancient One, when he appears in Marvel comics, is roughly five hundred years old and is searching for a successor when Doctor Strange’s comics begin. Though Mordo is his first choice to receive the Sorcerer Supreme title, Strange usurps Mordo in training, and the Ancient One gives him the title instead before kicking the bucket.

Marvel could make the argument that the MCU’s Ancient One — and original Sorcerer Supreme — is simply another person holding the same title as the comics’ nameless character, but the next step in logic suggests a different Ancient One might not live in Tibet. Doctor Strange defines the magical system in our world as covering the globe with protective shields, located in Hong Kong, London, and New York City, so the Ancient One’s training facility could really exist anywhere.

Interestingly, Marvel’s explanation for its character restructuring is the first instance of “The Ancient One” being a title. In the comic text, the only title in question is Sorcerer Supreme. The film, of course, reveals that Tilda Swinton’s character has been prolonging her life by siphoning power from the Dark Dimension. This means she’s been using its abilities, and Dormammu’s influence, while denying that power to other sorcerers who might want it: Kaecilius, for example, or Mordo.

At the end of Doctor Strange, no one receives either the Ancient One title or the Sorcerer Supreme title, though it appears Doctor Strange will protect the New York City sanctum, and his buddy Wong will protect the sanctum in Hong Kong. London is up for grabs, as is the Sorcerer Supreme title. Whether Strange will have to adopt the Ancient One’s title — and her method of lengthening his mortal life — will also be determined in Strange’s next appearance, which, according to Doctor Strange will likely be in 2017’s Thor: Ragnarok.